Download a file conversion program designed for e-book files. With the growing popularity of e-books and e-readers, you have a variety of programs from which to choose. You may want to start by looking into Calibre, Mobipocket Creator or Convert LIT.
Open the file conversion program and navigate to your .LIT file to upload it into the program.
Choose the options that allow you to convert your file. Make sure that the output is set to .PRC.
Load the completed .PRC file onto your Kindle by either emailing the file to your device or by using the data cable. If you are using the Kindle for PC application, double-click the file to open it on your computer.